1. Field of the Invention
The disclosures herein generally relate to an image forming apparatus, a medium feed control method, and a computer program.
2. Description of the Related Art
There is an automatic tray selection technology for feeding a print medium in an image forming apparatus. A plurality of trays are provided to store different media having different attributes such as different sizes and types, and these medium attributes are managed on a tray-specific basis. With automatic tray selection, one of the trays that stores a desired medium is selected to feed the medium at the time of printing to form an image.
It is often the case that an image forming apparatus is provided with a manual feed tray in addition to the trays subjected to automatic tray selection. In general, the trays subjected to automatic tray selection are used to store media that would be frequently used. A manual feed tray, on the other hand, is used to feed a medium of size and type that is not frequently used. Because of this, it is often the case that no medium attribute is managed for the media stored in a manual feed tray, or that only part of the attributes are managed for the media stored in a manual feed tray. Such a manual feed tray is not subjected to automatic tray selection.
Japanese Patent Application Publication No. 2006-224379 discloses a print system technology that has a function to switchover a feed inlet to include a manual feed tray as one of the trays subjected to automatic tray selection. In this technology, a preset setting is made to determine whether to feed a paper sheet from a manual feed tray if a tray storing a required medium among the trays subjected to automatic tray selection is empty.
The technology disclosed in the above-noted patent document, however, always selects a manual feed tray to feed a paper sheet if the tray storing a required medium is empty, regardless of what type of medium is stored in the manual feed tray. Error will thus occur if the size of the fed paper sheet is different from the required size.
A manual feed tray is often used for the purpose of feeding a special-type sheet such as an OHP (overhead projector) sheet or a heavy paper sheet. If such a special-type sheet is subjected to duplex printing or various finishing, troubles such as a paper jam or a mechanical failure of the finishing module may occur.
There is thus a need for an image forming apparatus, a medium feed control method, and a computer program that can perform automatic tray selection based on the attributes of a medium stored in a manual feed tray when the manual feed tray is used as one of the trays subjected to automatic tray selection.